616
FXUS65 KBYZ 220713
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
113 AM MDT MON JUN 22 2026
KEY MESSAGES
- ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS TODAY. A FEW
THUNDERSTORMS MAY BECOME STRONG TO SEVERE MAINLY EAST OF
BILLINGS. MAIN THREATS ARE HAIL, STRONG WINDS, AND HEAVY RAIN.
- MAINLY DRY AND TRENDING WARMER TUESDAY AND WEDNESDAY.
- DAILY CHANCE OF PRECIPITATION THURSDAY INTO THE WEEKEND.
- A STRONG WEATHER SYSTEM MAY (MODERATE CHANCE) BRING MORE
WIDESPREAD PRECIPITATION AND MOUNTAIN SNOW TO THE AREA OVER THE
WEEKEND. STAY UP TO DATE WITH THE LATEST FORECAST.
DISCUSSION
TODAY THROUGH SUNDAY...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE FORECAST THIS
MORNING AHEAD OF AN APPROACHING COLD FRONT. WHILE INSTABILITY
LOOKS TO BE ENOUGH TO SUPPORT A HEAVIER SHOWER OR THUNDERSTORM AT
TIMES, THE CHANCE OF SEEING A SEVERE THUNDERSTORM EARLY THIS
MORNING IS VERY LOW. THIS CHANGES LATE THIS MORNING INTO THIS
AFTERNOON AND EVENING WHEN ADDITIONAL SHOWERS AND THUNDERSTORMS
ARE FORECAST TO DEVELOP AS A COLD FRONT MOVES THROUGH THE AREA.
WITH THIS, MODEST INSTABILITY (CAPE VALUES AROUND 250 TO 1250
J/KG), GOOD SHEAR (35 TO 45 KNOTS) DUE TO AN APPROACHING JET
STREAK, AND ELEVATED PRECIPITABLE WATER VALUES (0.75 TO 1.00 INCH)
WILL SUPPORT THE POTENTIAL FOR A FEW STRONG TO SEVERE
THUNDERSTORMS. AT THIS TIME, THE STORM PREDICTION CENTER HAS A
MARGINAL RISK (1/5) OF SEVERE THUNDERSTORMS OVER SOUTH- EASTERN
MONTANA AND NORTH- CENTRAL WYOMING AND A SLIGHT RISK (2/5) OF
SEVERE THUNDERSTORMS OVER NORTH-EASTERN WYOMING LATE THIS MORNING
INTO THE EVENING. THE MAIN THREATS WITH ANY STRONG TO SEVERE
THUNDERSTORM THAT DEVELOPS ARE HAIL UP TO HALF DOLLAR SIZE (1.25
INCHES), STRONG WIND GUSTS OF 60+ MPH, AND HEAVY RAIN. THE ONE
WRINKLE IN THIS SEVERE THUNDERSTORM POTENTIAL IS THE MORNING
CONVECTION AND ASSOCIATED CLOUD COVER OVER EASTERN MONTANA, WHICH
MAY STABILIZE THE ATMOSPHERE AND LIMIT THE STRENGTH AND EXTENT OF
THUNDERSTORMS LATER IN THE DAY. ON THAT NOTE, THIS CONVECTION AND
CLOUD COVER MAY CLEAR OVER SOUTH-CENTRAL MONTANA EARLIER IN THE
DAY, SO WHILE THIS AREA IS AT A LOWER RISK OF SEVERE WEATHER, IT
IS AN AREA TO WATCH SHOULD BETTER DIURNAL HEATING DEVELOP.
CURRENTLY, A FEW OF THE CONVECTIVE ALLOWING MODELS (CAMS) DO SHOW
A STRONG TO SEVERE THUNDERSTORM DEVELOPING THAT FAR WEST, SO IT IS
SOMETHING TO WATCH.
TUESDAY WILL BE A DRIER DAY AS CYCLONIC FLOW IS REPLACED BY AN
APPROACHING LOW AMPLITUDE RIDGE. WITH THAT SAID, THERE MAY BE
ENOUGH ELEVATED INSTABILITY IN THE CYCLONIC FLOW TO SUPPORT A
LIGHT SHOWERS MAINLY NEAR THE MOUNTAINS AND FOOTHILLS (10 TO 25
PERCENT CHANCE). WEDNESDAY WILL BE ANOTHER MOSTLY DRY DAY, THOUGH
A SUBTLE WAVE AHEAD OF THE LOW AMPLITUDE RIDGE MAY BRING LIGHT
SHOWERS TO THE AREA DURING THE DAY (10 TO 50 PERCENT CHANCE,
GREATEST OVER THE MOUNTAINS).
THE WEATHER PATTERN LOOKS TO BECOME MORE ACTIVE THURSDAY AS A
MORE ROBUST SHORTWAVE MOVES THROUGH THE REGION. WHILE SOME
UNCERTAINTY IN THE DEPTH OF THIS WAVE EXISTS BETWEEN MODELS, THERE
LOOKS TO BE ENOUGH INSTABILITY AND LIFT TO FAVOR AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS (MODERATE CHANCE). DEPENDING ON
THE DEPTH OF THE WAVE, A FEW STRONG TO SEVERE THUNDERSTORMS COULD
ALSO DEVELOP (LOW CHANCE).
FRIDAY INTO THE WEEKEND, A LARGE WEATHER SYSTEM IS EXPECTED TO
MOVE INTO THE NORTHWESTERN UNITED STATES IN SOME FASHION. WHILE
QUITE A BIT OF UNCERTAINTY REMAINS IN THE TRACK OF THIS WEATHER
SYSTEM, ENSEMBLE FORECASTS SUGGEST PRECIPITATION, COOLER
TEMPERATURES, AND WINDY CONDITIONS WILL IMPACT PORTIONS OF THE
NORTHWESTERN UNITED STATES DURING THIS TIME. AS FOR OUR AREA,
SHOWERS AND THUNDERSTORMS ON THE LEADING EDGE OF THE WEATHER
SYSTEM ARE CURRENTLY FORECAST ON FRIDAY. DEPENDING ON WHERE THE
CORE OF THE LOW PRESSURE SYSTEM GOES SATURDAY INTO SUNDAY, OUR
AREA COULD SEE MORE WIDESPREAD PRECIPITATION FOR THE WEEKEND, OR
DRIER AND MORE WINDY CONDITIONS. IN ADDITION, THIS WEATHER SYSTEM
MAY HAVE ENOUGH COLD AIR ASSOCIATED WITH IT TO SUPPORT SNOW OVER
THE HIGHER ELEVATIONS OF THE MOUNTAINS (MODERATE CHANCE). IF YOU
HAVE OUTDOOR OR TRAVEL PLANS LATE THIS WEEK INTO THE WEEKEND,
ESPECIALLY IN THE MOUNTAINS, MAKE SURE TO STAY UP TO DATE WITH THE
LATEST FORECAST. LA
AVIATION
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL MOVE WEST TO
EAST DURING THE OVERNIGHT HOURS. BRIEF MVFR CONDITIONS ARE
POSSIBLE UNDER THUNDERSTORMS. FAR SOUTHEAST MT HAS ABOUT A 20%
CHANCE FOR FOG/LOW STRATUS INTO THE EARLY MORNING HOURS,
PRECEDING OR MIXED WITH LIGHT RAIN. MVFR CEILINGS WILL MOVE INTO
NORTHWEST AREAS AFTER 12Z AND MAY AFFECT KBIL, LIFTING INTO THE
AFTERNOON. A FEW STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE OVER
FOR AREAS GENERALLY EAST OF KBIL THIS AFTERNOON, LASTING THROUGH
THE EARLY EVENING. THE MAIN THREAT WITH THESE STORMS WILL BE LARGE
HAIL, STRONG WINDS AND HEAVY RAIN. MVFR TO IFR CONDITIONS ARE
POSSIBLE WITH THE THUNDERSTORMS THIS AFTERNOON AND EVENING. STP
PRELIMINARY POINT TEMP/POPS
TDY TUE WED THU FRI SAT SUN
-------------------------------------------------------
BIL 072 051/075 053/076 053/081 055/089 060/077 051/069
4/T 30/U 12/T 13/T 21/B 48/T 75/T
LVM 073 044/075 046/075 046/079 048/085 049/069 041/062
3/T 20/U 01/B 24/T 22/T 49/T 87/T
HDN 073 048/075 049/076 050/081 053/089 058/078 049/071
5/T 40/U 12/T 15/T 31/B 37/T 86/T
MLS 071 049/072 048/073 050/078 054/083 058/079 053/070
5/T 50/U 01/B 03/T 41/B 45/T 65/T
4BQ 072 051/071 048/072 050/076 054/083 059/080 053/070
6/T 60/B 02/W 26/T 51/B 36/T 86/T
BHK 071 046/070 043/071 045/075 050/078 054/079 050/070
5/T 50/N 01/B 01/B 41/N 46/T 76/T
SHR 072 047/069 045/072 046/076 049/086 054/077 046/068
5/T 52/T 34/T 37/T 32/T 27/T 77/T
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
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